[PATCH 1/2] efi_loader: correct reported length in GetNextVariable()

[Punit Agrawal]

Hi Heinrich,

Heinrich Schuchardt <xypron.glpk at gmx.de> writes:

> The runtime service GetNextVariable() returns the length of the next
> variable including the closing 0x0000. This length should be in bytes.
>
> Comparing the output of EDK2 and U-Boot shows that this is currently not
> correctly implemented:
>
> EDK2:
> OsIndicationsSupported: 46
> PlatformLang: 26
> PlatformLangCodes: 36
>
> U-Boot:
> OsIndicationsSupported: 23
> PlatformLang: 13
> PlatformLangCodes: 18
>
> Provide correct length in GetNextVariable().
>
> Fixes: d99a87f84b75 ("efi_loader: implement GetNextVariableName()")
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  lib/efi_loader/efi_variable.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> index c316bdfec0..04ead34c6f 100644
> --- a/lib/efi_loader/efi_variable.c
> +++ b/lib/efi_loader/efi_variable.c
> @@ -299,7 +299,7 @@ static efi_status_t parse_uboot_variable(char *variable,
>  	p = variable_name;
>  	utf8_utf16_strncpy(&p, name, name_len);
>  	variable_name[name_len] = 0;
> -	*variable_name_size = name_len + 1;
> +	*variable_name_size = sizeof(u16) * (name_len + 1);

Maybe I am missing something, but isn't a similar fix needed in the
function where the buffer is checked for sufficient size?

For context, I am referring to

	if (*variable_name_size < (name_len + 1)) {
		*variable_name_size = name_len + 1;
		return EFI_BUFFER_TOO_SMALL;
	}

Thanks,
Punit

>
>  	/* guid */
>  	c = *(name - 1);
> --
> 2.25.1